Isolation and analysis of a linear plasmid-located gene of Borrelia burgdorferi B29 encoding a 27 kDa surface lipoprotein (P27) and its overexpression in Escherichia coli.

Using an antiserum of a patient with cutaneous manifestations of Lyme borreliosis we have isolated the gene encoding a 27 kDa protein antigen (P27) of Borrelia burgdorferi B29 from a lambda-gt11 expression library. Nucleotide sequence analysis revealed that it is a basic protein of 248 amino acids with a typical prokaryotic leader sequence of 17 amino acid residues at the N-terminus of the proposed translation product. Biochemical investigations showed that P27 is a surface-exposed lipoprotein. From pulsed-field gel electrophoresis and subsequent Southern blot analysis it is evident that the p27 gene is located on a linear plasmid of a size of approximately 55 kb. It was overexpressed in Escherichia coli and the purified recombinant protein was used for biochemical and serological studies. Northern and Western blot analysis demonstrated that p27 is expressed in the European B. burgdorferi strain B29, but not in the American strain B31.